Method and apparatus for bending sheet metal



A. C. BENNETT METHOD AND APPARATUS FOR BENDING SHEET METAL .Filed June 26, 1923 '7 Sheets-Sheet 1 INVENTOR WITNESSES ATTORNEY Oct. 5 1926.

A. C. BENNETT METHOD AND APPARATUS FOR BENDING SHEET METAL 7 Sheets-Sheet 2 Filed June 26, 1923 INVENTOR/ V WITN ESSEB ATTORN EY I Oct. 5

A. C. BENNETT METHOD AND APPARATUS FOR BENDING SHEET METAL Filed June 26, 1923 7 Sheets-Sheet 5 R O T N E V m ATTORN IY 7 Sheets-Sheet 4 v THU H A. C. BENNETT Filed June 26 METHOD AND APPARATUS FOR BENDING SHEET METAL Oct; 5 1926.

INVENTOR,

ATTORNEY 1 Hill II [HHIII IHIIIII lllll ll I III Oct. 5 1926. 1,601,992

A. c. BENNETT METHOD AND APPARATUS FOR BENDING SHEET METAL Filed June 26, 19?" '7' Sheets-Sheet 5 INVENTOR WITNESSES Q I BY ATTORN Y A. C. BENNETT Opt. 5

METHOD AND APPARATUS FOR BENDING SHEET METAL Filed June 26, 1923 7 Sheets-Sheet 6 INVENTOR,

WITNESSE8 ATTO R N BY Oct. 5 1926.

A. c. BENNETT MBTHQD AND APPARATUS FOR BENDING SHEET METAL Filed June 26, 1923 7 Sheets-Sheet 7 INVENTOR m,

WITN ESQ ES ATTORN IY Patented pct. 5, 1926.

AZZEL BENNETT, OF I-ITJ'DSON', NEXV YOBI L'ASSIGNOB TO GIFFORD-'WOOD COMPANY,

or Henson,

NEVI' YORK, A CORPORATION OF NEVJ YORK.

METHOD AND .APPABA'DUSFOR SENDING SHEET METAL.

v Application filed June 26 1923. Serial No. 647,869.

This invention relates to a method and apparatus for bending sheet metal, and in the present exempliiication is. used in the manufacture of rectangular ice cans for attaching the bottoms thereto.

The object of the invention. is, broadly, to provide improved means for bending the metal, and particularly for uniting the same to form a lock joint, whereby a superior article may be produced from sheet metal with economy of time and labor.

A further object of the invention is to provide a method of bending and uniting the edges of the metal to form a double lock joint, which forms a reinforcing flange aroundthebottom of the can, mak ng it particularly strong and durable for the purpose for which it is designed.

In carrying out the invention in the manner herein described in connection with the construction of a rectangular can, adapted to be used in the manufacture of artificial ice, the body of the can, comprising the four side walls, is first made in any preferred manner with the lower edges slotted at the corners to form the bent. The bottom, which has been previously formed with downturned peripheral flanges, also slotted at the corners is then placed in position within the side walls, and the work suitably clamped. The lower edges of the side wall flanges are then bent inwardly through an arc of 180 over the bottom flanges to form a lock consisting of three thicknesses of metal. These three thicknesses are then bent again through an arc of 180 to form a double locked flange of five thicknesses around the bottom of the can. Solder is also usually applied to finish the joint and make it liquid tight.

lVith the above general objects in View, the invention also includes numerous improvements in the details of construction and combinations of parts which are of general appl cation in the art of metal bending, and which will be more fully explained in the following detailed description taken in connectionwith the accompanying drawings.

In the drawings:

Figure 1 is a front elevation of the mechanism to which the invention relates.

flanges which are to be widest side,

, Fig. 2 is a plan view of the same with the can clamping mechanism removed. Fig. 8 is a side elevation of the same with the parts just beginning to operate. Fig. 4 is a rear elevation of the operating mechanism.

' Fig. 5 is a side elevation of the principal working parts of the bending mechanism in a position of rest.

Figs. 6, 7 and 8 are similar views showing the successive positions of the same during the bending operation.

Fig. 9 is a detailsectional view showing the clamp arm, and means for actuating the same to engage the work.

Fig. 10 is a detail sectional view of the clamp arm and means for raising the same, after the first stage of the'operation is completed.

Figs. 11, 12 and 13 are enlarged sectional views showing the work and the relative position of the bending crank at diiferent stages of the operation. V

Fig. 14; is a detail view of the means for operating the can clamping mechanism.

The operating mechanism for the various parts of the machine is supported on a suitable base 1, at the front side of which is an upwardly extending frame 2, having a table 3 at its upper end on which the wor r is supported and held while the various operations are being performed. In the specific form of the invention herein shown, the table 3 serves as a support for a rectangular can body e, which is held on its as indicated in full lines in Figure 1, while the lower edge thereof is bent, and is afterward held on its narrow side, as indicated'in dotted lines, while the same operation is performed on the narrow side. This is repeated for all four sides. The means for clamping the can body while this work is being performed is supported on the upwardly evtending side frame pieces 5 and 6. The construction and operation of this can clamping mechanism will be more particularly described later.

As indicated in Figs. 11, 12 and 13, the bottom 7 with its downturned flanges 8 is inserted within the can body 1, so that the lower portion 9 of the side walls of the can body extends beyond the flanges 55. The flanges 8 and lower portions 9 are slotted at the corners as indicated at 8 and 9. These extended portions 9 are then folded inwardly through an angle of 180, until the flange 8 is clamped between the body 4 and flange 9 to form three superposed thicknesses of metal. The work is then advanced and the same operation is repeated, and the three thicknesses folded over to form a flange 10 consisting of five thicknesses of metal.

The mechanism for effecting the above de scribed bending operation will now be described. In the form herein shown, all of this mechanism as well asthe clamping mechanism is operated through the medlum ofan electric motor 11, supported by the motor base 12. The motor shaft 13 is provided at one end with a small pinion 14, which drives a gear 15 loosely mounted on a 'count'ershaft 16, which is journaled in bearings 16 on the base 1. A friction clutch 17 serves to operat-ively connect the gear 15 with 'a countershaft 16. This clutch is shifted by means of a clutch. collar 18 having a pin and slot connection 19, with a yoke 20 formed at the lower end of a shifting lever 21, which is pivotally supported at its lower end in bearin 's 22, as shown in Fig. 4. A pinion 23 rigidly secured to one end of shaft 16 is in driving engagement with a gear 24 secured to a shaft 25, which is mounted in suitable bearings 26 on the main supporting base 1. This shaft constitutes the main drive shaft from which the various working parts of the machine are actuated.

The shifting lever 21. is adapted to be manually shifted to the position shown in full lines in Fig. 4, to engage the clutch 17 and start the bending mechanism into operation, and when the cycle of operations'is completed, the lever is automatically shifted to the dotted line position to disengage the clutch. This automatic throw-out mechanism consists of a rock shaft 27, having at one end an arm 28 connected by a link 29 to the level 21, and having at its other end an arm 30, adapted to be engaged by a lug 31 on the side of the gear wheel 24 at each revolution of the latter.

Above the main drive shaft 25, a short rock shaft 32 is journaled in a. bearing 83, which is suitably supported above the intermediate bearing 26 of the main drive shaft. A clamping arm 34 has rearwardly extending ears 35 and 36, which are rigidly connected to the rock shaft 82. The front end of the clamping arm 34 terminates in a downturned lip 37 adapted to clamp the work at the forward edge of the table 3, as seen in Fig. 9. The forward end of the arm 34 extends substantially throughout the width of the widest side of the can, as

shown in Fig. 1. The forward end of the arm 34 is also slotted at 38 to receive the edge of the can 4 so as to permit the narrow side of the can to be clamped, as shown by dotted lines in Fig. 1. "An anti-friction roller 39, journaled between the ears 36, is engaged by a cam 40 secured to the main drive shaft 25 toforce the flange 37 into clamping relation to the work, as soon as the operation of the machine is started. After the edge of the metal has been bent 90, the clamp arm 34 is raised to the position shown in Fig. l0,' while the remainder of the bending operation is completed. This movement of the clamp. arm is eifected by means of a depending linger 41 formedii r tegralwith, one of the cars 35, and engages able by a cam 42 secured to the shaft 25."

The bending operation is effected by a bending crank 43., which extendsa'cress "the machine, and in its normal position, when the machine is at rest, occ'upisthe position shown in Fig. 11, with the edge ortion of the flange 9 restingon its upper ace. .The bend ing'crank 43 is integrally co lllficted with a shaft 44, the axis of'which' is in alinement with the line on which the metal is' to be:

end of the shaft 4, :fcarries a 45, which acts in themanner of bent. Qne

bending disk a crank to rock the shaft'44 to perform the bending operation. Thesu c'cessive steps of this operation arejaccompli'shed through the medium of radial slots 46. and 47, which'are successively mounted in the extremities ofa drivingdisk 50, which is secured to, the drive shaft 25. The latch 51, which is pivoted at 5,2 to the d 2 he main f ame, has an uptu n d finger at its forward end, which engages successively the notches '54 and in the periphery of the crank disk 45 to hold the latter d the ending rank. .3 in. a fixed position temporarily between the several stages of the bending process. The rear end of this latch is of suflic'ient weight to normal; ly hold the finger53 in engagement with the disk 45, and has ,1 arcu'ate portionhli concentric with theshaft 25 57, 58 and 59- respectively, secured to the disk 50, and operable to disengage the latch from the disk 45 during the ing steps, and subsequ ent ly during 'thereturn or the disk 45 and snaf 44m the r initial PQSltlOll ready for the next bending 0peration. Forthe sake of 'c-lear'ne'ss I have shown only one set of disks 45"and with their associated parts fordrivingthe shaft.

44,-but these are aref'erably duplicated at the other end of the shaft,

A sprocket c hai'n GO connects a sprocket wheel 61 rigidly secured to'the shaft 44, with a sprocket wheel 62, which is provided with a spl t collar 63 adjusted to frictionally engage the shaft 25, but permitting the engaged by rollers 48." and 49 I and'enfgageable at certain periods of the operation by pins successive bench latter torotate independently of the sprocket gear, while the sprocket wheel 61 and disk 45 are positively held against rotation or are positively driven in the opposite direction to effect the bending operation.

When the work has been placed in position on the table 3, with the portion to be bent resting on the upper face of the bending.

crank 43, the work is clamped in position by means hereinafter described, and the clutch shifting lever 21 is swung to the position shown in full lines in Fig. 4 to engage the clutch. The gear 24 and shaft 25 then commence to rotate in the direction of the arrow in Fig. 3, and the pin 57 rides under the arcuate portion 56 of the latch, as shown in Fig. 5. At the same time the widest portion of the cam rides under the roller 39, causing the flange 37, on the forward end of the clamp arm 34,.t-o firmly clamp the work against the rear edge of the table 3. Further rotation of the shaft 25 and disk 50, from the position shown in Fig. 5, causes the roller 48 to enter the slot 46 and to rotate the disk 45, shaft 44, and bending crank 43 in the opposite or anticlockwise direction, while the'sprocket wheel 62 and split collar 63 slips on the shaft 25. This movement continues until the parts reach the position shown in Fig. 6, in which the bending crank 43 has been revolved through an arc of 90 bending the edge of the metal at right angles to the portion clamped by the arm 34. As the roller 48 leaves the slot 46, the pin 57 leaves the arcuate portion 56 of the latch, and permits the finger 53 to engage the notch 55 and hold the disk and the bending crank 48 stationary, while the cam 42 engages thev depending finger 41 of the clamp arm 34, as shown in Fig. 10, and raises the lip 37 out of the path of operation of the bending crank By the time that the clamping arm 34 has been raised to this position, the pin 58 engages the 'arcuate portion of the latch 51 to again release the disk 45, while the roller 49 enters the slot 47, as shown in Fig. 7. This operation continues until the disk 45 and bending crank 43 have completed the remainder of their rotation through an angle of 180, bending the bended flange back upon itself, or upon an interlocking flange 8, as shown in Fig. 12.

As soon as the roller 49 leaves the slot 47, the disk 45 is free to return to its initial position, which it does by reason of the sprocket connection 60. The frictional en gagenient of the split collar 63 with the shaft 25 is sufficient to effect this return movement when the disk 45 is no longer constrained by engagement with the driving disk 50. During this return movement of the disk 45, the third pin 59 engages the arcuate portion'56 of the latch, thus permitting the notch to pass the finger 53, and by the therefore engages with the notch time the notch 54 has reached the finger 53, the pin 59 has left the latch, and the latter 54 and locks the disk 45 in its initial position. Immediately after this, the lug 31 on the gear 24 engages the arm 30 of the rock shaft 2T-and disengages the clutch 17, so that the drive shaft 25 also comes to rest, but'not, however, until the inertia of the moving parts have carried the lug 31 past the arm 30. After the shifting lever 21 has been thus automatically swung to disengage the clutch, the latter remains disengaged until'the lever 21 is manually returned to start another cycle of operation.

hen this first bending operation has been completed, as shown in Fig. 12, the can clamping mechanism, hereinafter described, is released while the can is advanced to the position shown in dotted lines in Fig. 13,

where the can is again clamped, and the cycle of operations is repeated to again bend the flange through an angle of 180 to form the five thicknesses, shown at 16 in Fig. The can clamping mechanism will now be described. Th s mechanism includes a rock shaft 64 journaled in the upper ends of the side frame pieces 5 and 6, and having a pair of forwardly extending clamp arms 65 rigidly secured thereto, and carrying at their forward ends a clamp bar 66, which is adapted to engage and clamp the can 4 when the latter is resting on its narrow side, as shown by dotted lines in Fig. 1. This clamping bar carries an auxiliary bar 67, which is equal in depth to the difference between the width of the widest side and the width of the narrowest-side of the can 4. Thus, when the can is laid on its wide side, it is clamped by the bar 67. Inasmuch, however, as the bar 67 only extends across half the width of the can,.it is advisable to provide a clamping finger 68, which is pivoted at 69 to the end of the clamping bar 66, and at its lower end is provided with a lip 7 0 adapted to engage the corner of the can. A crank shaft 71 is journaled in a bracket 7 2 adjacent the upper end of the clamping finger 68, and is provided with a finger 73 engageable with the upper end of the clamping finger to move the latter into engagement with the can, as shown in full l nes in Fig. 1. A weight 74 may be secured to the crank shaft 71 to hold it normally with the finger 73 raised, and in position to be swung into engagement with the clamping finger 68 when desired. The rear ends of the clamping arms 65 have a weight 7 5 secured thereto, which normally hold the clamping bar 66 r sed so that the work may be inserted or removed. The rock shaft 64, as soon as the operation is started, is automatically rocked to bring the clamping bar 66 into clamping position by a push rod76, which is pivotally connected at its upper end to a rearwardly extending finger T? on the rock shatt 6,4, and at its lower end is provided with a yoke 78, in which is jour naled a roller 79. The push rod Y6 is slidably mounted in a block 80 secured. to the side frame piece 5, in such a relation that the roller 79 is in the path of a cam 81 carried by the end of shaft 25. During the entire bending operation, therefore, the roller 79 rides on the large portion of the cam 81, and maintains the clamping bar 66, or the auxiliary clamping bar 67, in engagement with the can. The push rod 76 is preferably made up of twotelescoping parts, which are urged into, extended position by a com pression spring 82, thus allowing for slight variations in the size of the cans.

It is tov be understood that the, specific form of clamping mechanism and the method of its actuation is merely illustrative, and that any to an of clamping mechanism may be used in connection with the bending mech anism. It will also be readily appreciated that the machine is not limited in its use to the making of cans, but is capable or being adapted to the bend ni of sheet metal wherever a lock joint is dcsi ed. it will also be observed that a bend of 90 in be made by startingthe operation as above described, and disen 'aging the clutch just before the roller 4-9 enters the slot 47. It is also. possible by changing the location of rollers 48 and 4.9 and the spacing of the slots at and t? to make bends of any angle des red. It is also obvious that numerous modifications may be made in the structure of the various parts and in the combinations thereof, as long as such modifications mark no material departure from the salient features of the invention as defined in the appended claims.

What I claim is:

1. In a metal bending machine, the com bination of upper and lower members for clamping the metal adjacent the bending line, a bending member engageable underneath the edge of the metal when so clamped, a power shaft, and means actuated by a continuous rotation t-hereoi to move the bending member for initially bending the edge of the metal against the edge of the upper clamping member, then raising the upper clamping member while the bend ing member remains stationary, and then continuing the movement of the bending member t complete the bending of the edge of the metal through an angle of approximately 180.

2. In a metal bending machine, the combination of a table on which the metal supported, a clamping arm, means for actuing the clamping arm to clamp the m tal. adjacent the bending line, a oivoted bending member engageable underneath-the edge of the metal, means for swinging the bending member upwardly about its pivot to initially bend the edge of the metal upwardly against the adjacent end of the clamping arm, means for then releasing and raising the clampin arm while the bending member remains substantially stationary, and means for subsequently continuing the movement of the heir ie ber about its pivot to complete the bending oi the edge of the metal through an angle of approximately 180.

in a metal bending machine, the combination of a stationary table adapted to receive-a rectangular sheet metal can body, means to clamp the can body with its side against the table, means for clamping the lower wall of the body adjacent the bendline, means for bending the bottom edge 1% body partially about said last-men tinned clamping means, then raising said cl mping means and continuing the bending til the be edge forms an interlock- .l

n placed within the body, and a main powe shatt ogeratively connectedwith all o said means for actuating the same.

at. In a metal bending machine, the comation of table on which the metal is a clampi arm pivoted in rear of table and having at its forward end a *urned lip, adapted to clamp the metal dge ot the table, with the edge of the rejecting over the edge of the table h said clamping arm, a power be of to en raising said clamping arm, and means operable by the further rotation of said shaft to cause a continuation oi the sprocket connection between the power shaft and crank for returning the initial position as soon as the s means is free from the slot.

6. in a metal bending machine, the combination of a work table, a bending crank, a main power shaft, intermittently engageable means for positively driving the bending crank from the power shaft to perform a bending operation, and a frictional drivlatter to its lot engaging ing connection constantly connecting the power shat and crank and operable to rock the latter backwardly to its initial posit on,

- to positively rotate eration, a frictional driving connection constantly connecting the power shaft and crank and operable to rotate the crank in the same direction as the power shaft as soon as the positively driven movement is completed, and a latch operable to lock the crank as soon as 1t reaches its initial posi tion.

8. In a metal bending machine, the combination of a worktable, a bending crank journaled with its upper surface normally forming a continuation of the surface of the table, the axis of said crank being coincident with the edge of the table, a clamping arm pivoted in rear of the table and having a downturned lip adapted to clamp the metal to the edge of the table, with the edge of the metal projecting over the bending crank underneath said clamping arm, means for initially actuating said clamping arm to clamp the metal, means for rocking the bending crank to bend the edge of the metal against the inner edge of said lip, means for then raising the clamping arm, and means for subsequently continuing the rotation of the bending crank to complete a bend of approximately 180.

9. In a metal bending machine, the combination of a table on which the metal is laid, a clamping arm adapted to clamp the metal to the edge of the table, of the metal projecting beyond the edge of the table, means for initially actuating said clamping arm to clamp the metal, a bending crank rotatably supported, means for rocking the same to bend the edge of the metal upwardly against the adjacent end of the clamping arm, means for then raising said arm, and means for subsequently continuing the-bending to complete a bend of approximately 180.

10. In a metal bending machine, the combination of a table, a bending crank rotatably supported and having a slotted crank disk secured at one end, a power shaft having means inter mittently engage'able with a slot in said disk the crank in a direction opposite to the rotation of the power shaft,

and a frlctionalconnection between the power shaft and crank for returning the latter to its initial position as soon as the slot engaging means is free from its slot.

11. In a metal bending machine, the combination of a work receiving table, a bending crank rotatably supported adjacent there tending forwardly from its pivot with the edge 7 adjacent the edge thereof to, a pivotally supported clamping arm exand overhanging the edge of the table having at its rear edge a depending portion, a power shaft journaled beneath the clamping arm, a slotted crank disk secured to the end of the bending crank, a cam secured to the power shaft operable through the initial part of its rotation to engage the clamping arm and to force it into clamping engagement with the work, a disk secured to the power shaft and having means engageable in one of said slots during substantially the first 90 of the rotation of the power shaft to positively rotate the bending crank, and a second cam on the power shaft so shaped as to engage the depending portion. of the clamping arm and raise'the latter after the first mentioned cam passes beyond the arm, and after the rollerleaves said slot.

12. In a metal bending machine, the combination of a work receiving table, a bending crank rotatably supported adjacent thereto, a pivo't ally supported clamping arm extending forwardly over the edge of the table and having a depending portion at its rear end, a power shaft journaled beneath the clamping arm, a crank disk secured to the end of the bending crank and having a pair of radial slots, a cam secured-to the power shaft and operable during the first part of its rotation to engage the clamping arm and to force it into clamping engagement with the work, a disk secured to the power shaft and having means engageable in one of said slots during substantially the first 90 of rotation of the power shaft to rock the bending crank in a direction opposite to the rotation of the power shaft, a second cam on the power shaft so shaped as to engage the depending portion of the clamping arm and raise the latter after the first mentioned cam passes beyond the arm and after the slot engaging means leaves the slot, means for temporarily locking the crank disk and bending crank while the crank arm is being raised, and means onthe power shaft disk engageable with the second slot upon further rotation of the power shaft after the clamping arm is raised until the bending crank is rotated through another angle of approximately 90.

. 13. In a metal bending machine, the combination of a. work receiving table, a bending crank rotatably supported adjacent thereto, a pivotally supported clamping arm adapted to clamp the work adjacent the edge of the table, a power shaft journaled beneath the clamping arm, a crank disk secured to the end of thebending crank and having a pair of radial slots, a cam secured to the power shaft operable during the first part of its rotation to engage the clamping arm and force it into clamping engagement with the work, a disk secured to the power shaft,

antl'carrying a roller engageable in one of said slots during substantially the first of the rotation of the power shaft to actuate the bending crank, a second cam on the power shaftso shaped as to engage the clamping arm and raise it out of clamping engagement after the first mentioned cam passes beyond the arm and after the roller leaves said slot, a latch operable to temporarily lock the crank disk and bending crank while the crank arm is being raised, a second roller on the power shaft disk ongageabl'e with the second slot upon further rotation of the power shaft after the clamping arm is raised until the bending crank has rotated through another angle of approximately 90, and a split sprocket connection between the power shaft and crank operable to rotate the crank backwa'rdly to its initial position as soon as the roller leaves the second slot.

14. A mechanism for forming a lock joint between the sides of a rectangular can body and a bottom having a downturned peripheral flange, said mechanism comprising means for engaging simultaneously the entire length of the lower edge of the can body and bending it inwardly through an arc of.

substantially 180 about the edge of the downtu-rned flange of the bottom after the latter has been placed within the body in such a position that the bottom edge of the body extends beyond the edge of the flange, means for thereafter advancing the can, and then by a second similar operation of said first-mentioned means bending the three thicknesses inwardly against the adjacent downturned edge of the bottom to form a double lock joint consisting of five thicknesses of metal. 7

15. A mechanism for forming a lock joint between the sides of a can body and a bottom having a downturned peripheral flange, said mechanism comprising a stationary table, means for holding the can body thereon with the bending line at the edge of the table, means for temporarily clamping the lower wall of the body adjacent the bending line, means for initially bending the metal upwardly while so clamped, means for then releasing and raising the clamping means, and for subsequently completing the bending of the metal through an angle of approximately 180 to form the joint.

16, In a metal bending machine, the combination of a table on which the metal is placed, a clamping member supported beyond the edge of the table and having an end engageable with the metal for clamping the same to the table with the edge of the metal projecting over the edge of the table, a bending crank with its upper surface normally forming a continuation of the surface of the table, means for operating the bending crank to first bend the projecting end of the metal, while it is clamped, through an angle of substantially 90, then releasing the clamping member while "the bending crank remains stationary, and then operating the crank to complete a bend of ap roxim a'tely 180 17. In a metal bending machine, the com bination of a table on which the metal is placed, clamping means for clamping the metal to the table with the edge of the metal projecting over the edge of the table, a bending member normally forming a continuation of the surface of the table with the projecting edge ofthe metal resting;- on the said bending member, a power shaft, and

means driven by a continuous rotation of said shaft for operating the bending menr her to impart to the metal an initial. bend of subs'tantiallyQO while it is clamped then releasing the clamping means while the bending member remains stationary, and then continuing the movement of the bending member to complete a bend of approximately 180.

18. In a metal bending machine, the eombination of a table 'on which the metal is placed, a clamping arm pivoted beyond the edge ofthe table and terminating in a downturned lip located above the edge of the table for clamping the metal thereto with l the edge of the metal projecting over the edge of the table, bending crank having its upper surface normally forming a continuation of the surface of the table so that the projecting edge of themetal may rest on said upper surface of the crank, means for temporarily releasing said clamping arm, and means for operating sai'd crank first to bend the metalagain'st the inside of said lip, while it is still clamped, and after the clamping arm is released, to "complete the bending of the metal to the desired degree.

19. The method of securing bottoms to rect'angiilar can bodies, which consists in forming the bottom with downturned peripheral flange, fitting the same within a straight body portion, with the bottom edge portion of the latter extending beyond said flange, clamping the adjacent'portions of the body and bottom together, while the edge portion of the body is initially bent inwardly substantially at right angles across the edge of said peripheral flange, then releasing said clamp and continuing the bending until a bend of 180 is completed to form a lock joint of three thickness'e's.

20. The method of securing bottoms to rectangular can bodies, which consists in forn'iing the bottom with a downturned peripheral flange, fitting the same within a straight body portion, with the bottom edge portion of the la ter extendin beyond said" flange, and folding the bottom bottoms to consists in forming the bottom with a downturned peripheral flange, fitting the same withm a straight body portion, with the bottom edge portion of the latter extending beyond said flange, clamping the adjacent portions of the body and bottom together while the edge portion oi the body is initially bent inwardly substantially at right angles across the edge of said peripheral flange, then releasing said clamp and continuing the bending until a bend of 180 is completed to :Form a lock joint of three thicknesses, then folding the three thicknesses inwardly in a similar manner through an angle of 180 to form a double lock of five thicknesses.

22. The method of securing bottoms to rectangular can bodies, which consists in "forming the bottom with a downturned peripheral flange, fitting the same within a straight body aortion, with the bottom edge portion of the latter extending beyond said flange, clamping the adjacent portions of the body and bottom together, while the edge portion oi the body is initially bent inwardly substantially at right angles across the edge of said peripheral flange, then releasing said clamp and continuing the bending until a bend of 180 is completed to form a lock joint of three thicknesses, then advancing the can, then clamping the same, then folding the three thicknesses inwardly at substantially right angles, then releasing the clamp, and completing the bending of the three thicknesses until a bend of 180 is formed thereby providing a flange of five thicknesses at the bottom of the can body.

In testimony, that I claim the foregoing as my own, I have hereto affixed my signature.

AZZEL C. BENNETT. 

